Paper 2021/524
Decentralized Multi-Client Functional Encryption for Set Intersection with Improved Efficiency
Kwangsu Lee
Abstract
Functional encryption (FE) is a new paradigm of public key encryption that can control the exposed information of plaintexts by supporting computation on encrypted data. In this paper, we propose efficient multi-client FE (MCFE) schemes that compute the set intersection of ciphertexts generated by two clients. First, we propose an MCFE scheme that calculates the set intersection cardinality (MCFE-SIC) and prove its static security under dynamic assumptions. Next, we extend our MCFE-SIC scheme to an MCFE scheme for set intersection (MCFE-SI) and prove its static security under dynamic assumptions. The decryption algorithm of our MCFE-SI scheme is more efficient than the existing MCFE-SI scheme because it requires fewer pairing operations to calculate the intersection of two clients. Finally, we propose a decentralized MCFE scheme for set intersection (DMCFE-SI) that decentralizes the generation of function keys. Our MCFE schemes can be effectively applied to a privacy-preserving contact tracing system to prevent the spread of recent infectious diseases.
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- Functional encryptionMulti-client settingPrivate set intersectionContact tracingBilinear maps.
- Contact author(s)
- kwangsu @ sejong ac kr
- History
- 2024-02-13: last of 2 revisions
- 2021-04-23: received
- See all versions
- Short URL
- https://ia.cr/2021/524
- License
-
CC BY